In general, an elevator landing door switch device for preventing intrusion of a person in a hoistway through a landing door is provided on each landing door. The landing door switch device, including an interlocking mechanism and a door switch, is configured to be released by mechanically interlocking with an elevator car door when the elevator car door is opened on arrival of the elevator car at a landing. When one of the landing door switch devices is released, operation of the elevator car is interrupted. Once the elevator door is closed, the landing door switch device is closed (i.e. the door switch is electrically connected) accordingly, and the elevator system resumes operation of the elevator car. With such configurations, not only can landing doors of an elevator be prevented from being opened improperly from the outside, but the operation of the elevator car can be interrupted appropriately when a landing door is opened on purpose or accidentally, thereby unforeseen accidents can be avoided in advance.
When a maintenance person enters a hoistway during maintenance and inspection of an elevator, a landing door switch device is released by unlocking its interlocking mechanism from the landing and opening the landing door manually, as known in the art. Therefore, the elevator car does not travel when the landing door is open.
However, in some elevators, the elevator car may resume operation once the landing door is completely closed during elevator maintenance, regardless of whether a maintenance person is in the hoistway. Further, even if the elevator has an inspection mode switch in addition to the landing door switch devices, there is always a chance that a maintenance person might forget to operate the safety switch, since the method of operating a safety switch differs depending on types of elevators.
Therefore, there exists in the art a need for providing a safety device of an elevator which can reliably stop operations of the elevator car at the time of elevator maintenance and inspection. There also exists in the art a need for providing a safety device for elevators capable of retrofitting for any type of elevators.